1. Field of the Invention
The present invention relates generally to vehicle sunroofs. More particularly the present invention relates to selective opacity sunroofs which extend between vehicle roof side rails and are retractable to allow opening of the passenger compartment of the vehicle.
2. Description of the Related Art
Sunroofs have long been a desirable feature of automotive type vehicles based upon their ability to create a opening in the vehicle roof skin and thereby provide a more open feeling to the passenger compartment. Obviously, the greater the area of the roof skin able to be uncovered, the greater will be the feeling of openess in the passenger compartment. Thus, makers of sunroofs have in the past provided various means of retracting sunroof panels rearwardly under or over the roof skin to provide open vehicle roofs. Sunroof makers have also sought to make these retractable panels serve as the roof skin for as much of the vehicle roof as possible both in the longitudinal and transverse axes of the vehicle. An early example of such a sunroof may be seen in U.S. Pat. No. 2,482,429 ('429).
However, with modern aerodynamic styling of automotive vehicles, certain structural changes have occurred in automobile roof construction which now necessitate adapting the structure and method of sunroof installation in order to provide the maximum roof skin opening.
Previously, an aperture was cut into the central portion of the original automobile roof skin to avoid the roof side rails. After cutting, a self-contained sunroof assembly, including a supporting frame and a movable panel; with its related hardware; were placed therein. Currently however, many automotive roof side rails are located closer to the longitudinal midline of the roof because the automobile doors extend into the plane of the roof for aerodynamic and styling reasons. To mount a self-contained sunroof mechanism in such a roof while avoiding the roof side rails, necessarily results in a narrower roof opening. Thus, the art now seeks to maximize the width of the sunroof while maintaining the aerodynamics of the vehicle. For example, U.S. Pat. No. 4,695,090 ('090) discloses the mounting of sunroof guide tracks within the original equipment side rails of automobile roofs. This mounting entails removing the top portion, if any, of the roof side rails and affixing the retractable sunroof guide tracks therein. The sunroof panel supported by the guide tracks is then extended door edge-to-door edge for the appearance of a sunroof panel covering the entire transverse area of the roof.
Thus, the prior art discloses either building the original roof structure to accommodate a maximally transverse, retracting sunroof panel, as in the '429 patent; or specially fitting individual sunroof assembly components into a slightly modified original vehicle roof frame, as in the '090 patent. The first option requires large initial tooling up costs to the original manufacturer for what may be a limited production run of vehicles. The second option requires different pieces for each type of vehicle roof frame and/or labor intensive retrofitting of the individual components to the slightly modified roof frame.
What is needed is a sunroof system which allows the retrofitting of an originally manufactured vehicle roof frame with a preassembled and self-contained sunroof assembly using parts readily adaptable to a variety of original equipment manufacture (OEM) roof frame types. This sunroof system should also retain the ability to provide a maximally transverse retracting sunroof panel. The present invention provides such a sunroof system.
A concurrent problem with known sunroofs which needs to be addressed, particularly as to maximally transverse sunroof panels, is the overabundance of sunlight admitted through a clear sunroof panel into a closed vehicle passenger compartment. While the presently popular clear sunroof panel has the advantage of allowing the vehicle passengers to see out through the vehicle roof, it affords little privacy to passengers, increases the greenhouse effect on the passenger compartment and lets the sun's rays prematurely age and fade the interior of the vehicle. As disclosed in U.S. Pat. No. 4,801,174 a prior solution to these problems was to add an additional sliding panel beneath the clear sunroof panel to act as a screen therefor.
Also known is the technique of applying an electrically operated laminate to automobile glass which can selectively vary its opacity according to desires of the operator. Such variable opacity laminated glazing may include suspended particle containing laminates such as liquid crystal or charged particle types as illustrated in Popular Science Magazine, November 1989 issue, at page 74.
Electrical connection to a selectively variable opaque window used as a sunroof panel is made difficult in that the sunroof panel must be movable, often not only longitudinally along the vehicle, but also up and down, as when the panel is to be retracted over the vehicle roof skin.
The present invention solves the aforementioned problems of the current art by providing a selective opacity sunroof panel with electrical power supplied thereto throughout the range of the sunroof panel movement.
The present invention thus provides a sunroof panel retractable to open the passenger compartment having a maximal opening in the transverse direction of the vehicle roof skin and whose opacity may be varied at the choice of the operator. The present invention is further adaptable to be easily added to a wide variety of automobile types as a retrofitted assembly.